Christina Aguilera and Nicole Richie's Secret Mommy Bond

Leaving the husbands at home, pals Christina Aguilera and Nicole Richie (who both became moms on the same day) hit the town last night.

It was a moms’ night out last night for Nicole Richie and Christina Aguilera. We’re not sure how long the pair have been friends but we do know that they share a special bond — they both became moms on the same day, giving birth (to Harlow and Max respectively) within hours of each other at Cedars-Sinai in Los Angeles on January 12, 2008.

The pair hit the West Hollywood nightclub Voyeur, joined by a few friends in a cozy corner booth. The group kept it fairly low key, but still sampled from the bottle of Grey Goose on the table. Nicole, who sported a sequined blazer, and Christina, dressed down in jeans, a white shirt and a fedora-like hat, hung out until around 1 a.m., when they were escorted — holding hands — through a back exit.

With cool moms like Christina and Nicole, wouldn’t it be sweet if little Max and Harlow ended up together?